With the development of technology, touch panels with touch control function have been applied more and more.
Capacitive touch panels become an important form of touch panels. As shown in FIG. 1, a capacitive touch panel comprises a plurality of touch driving electrodes Tx parallel to each other and a plurality of touch sensing electrodes Rx parallel to each other, which electrodes are all controlled by a control unit 100. The plurality of touch sensing electrodes Rx parallel to each other are disposed to overlap the touch driving electrodes Tx, thereby forming capacitors at the intersections between these two types of electrodes. As long as the driving electrodes are input with driving signals in order in scanning, sensing electrodes will generate respective sensing signals thereon correspondingly. When a touch action occurs, phenomena, such as electrode discharge, changes in the distances between electrodes, and changes in dielectric constants between electrodes, would appear at the touch point, and they can cause change of capacitance there. Thereby, when a driving electrode is scanned, the sensing signal over the sensing electrode corresponding to the touch point would also undergo change. In this way, it is possible to determine the touch position and implement touch control.
In order to reduce costs, reduce thickness and increase light transmittance, generally touch structures are converted more to the in-cell touch type. That is, the above-mentioned touch driving electrodes Tx and touch sensing electrodes Rx are disposed directly in the display panel, which means the touch panel itself can have both display function and touch function. For an in-cell touch panel, touch sensing electrodes Rx and touch driving electrodes Tx can also be used together with other electrodes for display so as to simplify the structure. For example, the above-mentioned touch driving electrodes Tx can also function as common electrodes (for liquid crystal display). In such a case, the touch panel needs to switch between display phases and touch phases alternatively, for example, entering a touch phase of 4 milliseconds each time after displaying one frame of picture. In this way, touch operation can not be implemented in the display phase, while display operation can not be implemented in a touch phase. However, since these two phases are switched very quickly, the user can not perceive it.